ENVS 1500 Lecture 29: ENVS 1500 Lecture 29 Notes
13 May 2018
School
Department
Course
Professor
ENVS 1500 Lecture 29 Notes – File Management
Introduction
• The concept of a file is central to the effective use of a computer system.
• A file is generally loosely defined as a collection of related information.
• Defined in this way, a file is a rather abstract concept
• Indeed, the contents of the file only have meaning in the context of their particular
internal description and use.
• Thus, the sequence of bytes in a file might represent a program, or a graphical image
• Maybe the alphanumeric text data for a book, to be used within a word processor
• A file may be organized internally into records or it may simply be a stream of bytes.
• A file constitutes a logical unit of storage, that is, logical to the person or program using
the file.
• The logical unit may or may not correspond to the physical storage characteristics of the
I/O device where it is stored.
• The file aageet syste proides ad aitais the appig etee a file’s
logical storage needs and the physical location where it is stored.
• The file management system identifies and manipulates files by the names provided by
their users.
• It determines the physical requirements of the file, allocates space for it, stores it in that
space, and maintains the information about the file so that it may be retrieved, partially
or in full, later.
• The file management system keeps track of the available space on each device
connected to the system.
• The user ad the user’s progras eed ot e aare of the uderlyig physial storage
issues.
• Users and programs simply access the files by name, and the file management system
handles the details.
• Generally loosely defined as a collection of related information.
find more resources at oneclass.com
find more resources at oneclass.com
